Radiological Concerns The primary radiological problems are the result of residual fission and activation products in the terrestrial environment. They have been identified by previous environmental surveys as follows: 1) External radiation levels significantly higher on some islands in an atoll compared to levels on lightly contaminated islands. 2) Fission and activation product radioactivity in certain terrestrial food items now growing on islands of these atolls and the possibility that unacceptable levels of these radionuclides may appear in foods, plants and animals newly introduced into these atolls. 3) Radioactivity in the ground water, a possible source of drinking water and water for irrigation, 4) Plutonium and americium isotopes in the surface soil. These factors are illustrated by data in Tables 1 through 4 taken from previous radiological survey reports. Table 1. = Bikini Island Gamma Radiation Rates in Bikini Atoll” - Weathered areas Close to shore Island center -Hot spots Eneu Nam (oR/hr) Exposure rate Range .010-,120 -910-.030 -020-,040 .950-.080 -080-,120+ -002-=,010 Maior contributors —ASICs 137 CS, 35 -010-,330 60¢0,*?"Cs .003-.010 x Aerokoj-Emenman complex: Aerokoj, Aerokojlol Bikdrin, Lele .001-.010 .006-,010 * ‘x East Eneman West Eneman .001-.010 -020-,570 Outer edge Island center N.E, corner Bokantuak, Iomelan, -010-.030 »015-.150 »110-,330 Rojkere, Eonjebi Eneman Enidrik East Enidrik West Enidrik .001+.570 .003=,235 -003-.030 -910-,235 Luko j .060-. 200 Bokbata .010=,030 Jelete Oroken Bokaetoktok Bokdrolul Aomen-Troij complex: Aonen Lomilik Odrik, Llroij -060-,130 015+.045 -910-.035 .020-.050 -005-.020 ,020-, 330 «010=,040 80¢9, 125g, 102m, 6069, 129ep, 102m, 8009, $55, Oma, bad we re $065, 13%cs B55, 12555 tek *see ref. 9, tk No soil sample or field spectra measurements. In some cases, the predicted doses and dose coumitments derived from survey information for Bikini and Enewetak Atolls approach or even exceed national and international radiacion protection standards for .certain living and dietary patterns, Corrective actions or restrictions mist be placed on use of these ratokis and their resources to assure that the applicable radiation standards are not exceeded. Herein lies the primary justification for the continuing environmental followup surveys sponsored by ERDA. Enviro mental Monitoring The most important sources of exposure to people living on Rongelap and to future residents of Bikini and Enewetak Atolls are from internal deposition of radioisotopes from certain elements in the human diet, and from the long term occupancy of islands having external rad{ation dose rates higher than natural background. Aside from periodic re-evaluations to escablish trends in external dose rate reduction, external radiation monitoring will assume less significance, compared to monitoring of the food chain, as time passes, At present, annual visits are being made to identify and collect repre- sentative samples of local diets for laboratory analysis and dose commitment updates. New locally grown food items are becoming available in small quantities on Bikini Island as a result of the experi- mental agricultural practices of a small group of caretaker families living there. Neither Bikini Atoll, where radiological cleanup has been completed, nor Enewetak Atoll where clean up has not yet begun, have a subsistence agriculture resource in being which is sufficient to support the anticipated populations which will one day live there (though such crops are currently being developed or planned). 9002331